Yes they can. For example a lot of shops will refuse £50 notes which are also legal tender. Legal tender means they can't refuse it as settlement of a debt, so for example a petrol station can't refuse it, because you have filled up your tank and you a required to pay for it. However if you take stuff to the till in a shop, you are not obliged to buy it, and the shop is not obliged to sell it, so there is no debt.

And supposing they do "shut the internet"? It happened in Egypt during the dying days of Mubarak's regime. Your bitcoins will be useless. Your gold coins will be worth a lot, although silver may be better for day-to-day transactions.

It doesn't make sense in terms of tax to own a rental property in a limited company. I would advise most people to own it personally or in an LLP. If they do their own management, then having a separate management company makes sense though.

You would have to pick the right ones. For every Microsoft or Google, there are hundreds of other companies that didn't make it, and remember that Google came along quite a bit later than most of the competitors they replaced.

Last time round, the telcos thought they could set up their own app stores, music stores and so on and get money from selling all that sort of stuff over 3G.
While we did eventually see those sorts of things available for sale on mobile devices, the money goes to companies that don't have a 3G licence, and the telcos just get to provide the bandwidth for transmitting it.
They now realise there isn't so much money to be made out of mobile internet, so that is why they bid a lot less this time round.

Correct, it was to repay the depositors. We will get our money back when the loans are repaid. They are mortgages so repayment isn't due yet. The last of them will be repaid in about 20 years from now.

If you rent from a private landlord, you have always had the "bedroom tax" if you rent too big a house. You look at the LHA rules for how many rooms you are entitled to, and then the LHA rate for that number of rooms in your area, and if your property is more expensive than that, you have to pay the difference.
What has changed is that this now applies to council and housing association properties. If you have too many rooms, you have to pay for the surplus ones.